This project addresses the hypothesis that viral infections can alter neurotransmitter function to cause neurologic and psychiatric diseases. A number of neurotransmitters have been mapped to locations within the central nervous system (CNS). Abnormal regional and whole brain levels of neurotransmitters are found in several neurologic and psychiatric disorders. The mechanisms by which neurotransmitter concentrations are altered in these disorders and the etiologic agents responsible remain largely unknown. Some viral infections are known to cause CNS dysfunction. Persistent viral infections can interfere with differentiated cell function with or without histologic injury. Neurologic and psychiatric disorders, particularly those associated with neurotransmitter abnormalities, may be linked to viral infections. During the last two years of this project, I will focus on Borna disease virus (BDV), an intriguing infectious agent with wide host range and tropism for selected CNS regions. BDV is important not only as a model for virus induced human CNS disease but also because BDV or a related agent may be directly implicated in neurologic and psychiatric diseases. My efforts will be directed toward characterization of this agent through analysis of cDNA libraries prepared from BDV infected rat brain RNA.